A) 550
B) 650
C) 750
D) None of these
Correct Answer: B
Solution :
Here, a = 4, d = 3, n = 20 so, \[{{S}_{20}}=\frac{20}{2}[2\,\,(4)+19\times 3]=10\,\,[8+57]=650\] If first term \[=a\] and last term \[={{a}_{n}}\] are given, then sum of terms of an AP is \[{{S}_{n}}=\frac{n\,\,({{a}_{1}}+{{a}_{n}})}{2}\] where, n = number of terms.You need to login to perform this action.
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